The basic principles of the art are taught in U.S. Pat. No. 3,485,120 issued Dec. 20, 1969. As is well known, continuous filamentary material such as tow may be cut into short, spinnable lengths by wrapping the tow about a revolving reel carrying a plurality of radially and outwardly facing, equally spaced knives or cutter blades. A pressure roller is forced against the outer surface of the material wound about the reel so that the material is cut into short lengths from the inside of the coil or winding thereof. By using razor-like blades which are accurately equally spaced about the reel, uniform lengths of fibers are continuously cut as the apparatus revolves.
The art was improved on in U.S. Pat. No. 3,744,361 issued July 10, 1973 and assigned to the assignee hereof wherein it was recognized that holding the pressure roller to its work by an unyielding means had some undesirable consequences. The U.S. Pat. No. 3,744,361 patent disclosed mounting the pressure roller for movement toward or from the reel assembly, and sensing the pressure of the fiber against the roller to effect such movement away from the reel assembly.
In this manner, the sharpness of the blades was monitored to indicate when they should be replaced. While the apparatus built in accordance with these teachings were satisfactory, they leave something to be desired in terms of monitoring the quality of the individual blades.